Expansion joint for concrete slabs

ABSTRACT

Two concrete slabs separated by a gap are interconnected by an expansion joint formed by a pair of metal profiles which have horizontal flanges flush with the upper slab surfaces and vertical webs projecting upwardly therefrom to the top of a traction layer supported by the slabs; the profiles have confronting projections extending into the gap and supporting a gable-shaped sealing strip of elastomeric material clamped onto these projections.

United States Patent 2,041,210 5/1936 Robertson Heinrich Honegger Wendelbuck 323, 8196 Wil Zurich, Switzerland July 16, 1968 Mar. 16, 1971 July 18, 1967 Switzerland inventor Appl. No. Filed Patented Priority EXPANSION JOINT FOR CONCRETE SLABS 8 Claims, 4 Drawing Figs.

U.S. Cl 94/18 Int. Cl E0lc 11/10 Field of Search 94/18 References Cited UNITED STATES PATENTS 2,267,220 12/1941 Robertson 94/18 FOREIGN PATENTS 896,034 5/1962 Great Britain 94/18 410,034 10/1 966 Switzerland 94/18 Primary Examiner-Jacob L. Nackenoff Att0rney Karl F. Ross ABSTRACT: Two concrete slabs separated by a gap are interconnected by an expansion joint formed by a pair of metal profiles which have horizontal flanges flush with the upper slab surfaces and vertical webs projecting upwardly therefrom to the top of a traction layer supported by the slabs; the profiles have confronting projections extending into the gap and supporting a gable-shaped sealing strip of elastomeric material clamped onto these projections.

Patented March 16, KQH

2 Sheets-Sheet l Heinrich Honegger INVENI'OR BY SS Attorney Patented March 1%, WW 3,57@,378

2 Sheets-Sheet 2 Heinrich Honegger INVENTOR.

K r 12D Attorney EXPANSIGN JOINT FOR CGNQRETE SLABS My present invention relates to an expansion joint for a roadway essentially composed of spacedly adjoining concrete slabs with traction layers of asphalt or the like supported on a generally horizontal upper surface of each slab.

The principal object of this invention is to provide an expansion joint of this type that is of simple construction while forming a dependable seal between the adjoining slabs and which minimizes the discontinuities therebetween.

Another object is to provide an expansion joint whose parts can be easily removed and replaced in the case of wear or for the purpose of accommodating surfacing layers of different thickness. It is also an object of my invention to provide an expansion joint which, upon a narrowing of the gap between adjoining roadway sections, tends to eject soil and rubbish previously accumulated therein.

My invention further aims at providing an expansion joint adapted to be used with all kinds of concrete slabs, i.e. precast slabs as wellas slabs cast in place, with or without protective frames or easements.

These objects are realized, pursuant to my invention, by the provision of a pair of metal profiles on opposite sides of a gap formed between a pair of adjoining slabs, each profile having a substantially horizontal flange received in a recess of the upper surface of a respective slab and an upstanding web riswhile being readily flattenable by traffic rolling over it.

To secure the sealing strip to these profiles, I prefer to design the confronting projections as rib members and to provide a pair of cooperating bar members which are vertically displaceable, with the aid of countersunk screws or the like, so that each edge of the strip can be gripped between one rib member and an associated bar member; depending on which of these two members lies above the strip, either the strip member or the bar member may be made flush with the top of the traction layer to reduce the effective separation of the two adjoining road sections.

The above and other features of my invention will become more fully apparent from the following detailed descriptions of certain embodiments, reference being made to the accompanying drawing in which:

FIG. I is a vertical sectional view of an expansion joint according to the invention, bridging a pair of spaced roadway sections;

FIG. 2 is an enlarged detail view of part of the joint of FIG.

FIGS. 3 and 4 are views similar to FIG. I, illustrating certain modifications.

In FIGS. 1 and 2 I have shown a pair of concrete slabs 2 separated by a variable gap 1 and forming part of respective roadway sections, the horizontal upper surface of each slab supporting a water-repellent coating 3 covered by a traction layer 4i of bituminous material or the like. An expansion joint 5 comprises a sealing strip 12 of natural or synthetic rubber (e.g. neoprene) supported by a pair of metal profiles (eg of steel) 6 symmetrically disposed on opposite sides of the gap. Each of these profiles 6 has a vertical web 8 and a horizontal flange 9, the latter being received in a recess '2" of the corresponding slab 2 and being flush with the upper surface thereof so as to support part of the layers 3 and 4. Web 8 which rises from a shoulder or ledge 18 of slab 2 and extends by a distance D above flange 9 to the top of traction layer 4, is formed with a rib 7 horizontally projecting into the gap at the top of the web; this rib 7 cooperates with a substantially coextensive underlying bar 14 between which a corresponding 'edge'of strip i2 is clamped. Rib 7 is formed with a series of bores 7 (only one shown) aligned with respective tapped holes 14' of bar 14, these bores being traversed by screws 13 which matingly engage the holes 14' and whose heads are countersunk in the rib 7. Confronting beads 7" and 14" of the two vertically spaced members 7 and 14, which both extend over the full width of the corresponding slab 2, bite into the strip 12 from above and below to hold it securely in position; corrugations l5 along'the strip edges ensure a fluidtight fit between the strip 12 and the clamping members 7 and 14. Spacing rings 17 surround the bolts 13 to limit the degree of compression exerted upon the clamped strip edges. A spring washer l6 prevents any spontaneous loosening of the screws l3'whose heads'have hexagonal sockets accessible from above for engagement by conventional Allen wrenches. to facilitate rods 11 L of are poured To help anchor the profiles 6 to the slabs 2, iron loops 10 of round bar stock are welded onto the webs 8 and the flanges 9 thereof and are imbedded in the concrete where they may also be welded to reinforcing rods 11. In order tofacilitate installation of the joints in the case of precast slabs, each slab 2 may be cast with narrow vertical cutouts 2 adapted to receive the loops I0; the sections of rodsll secured to these loops may be initially cutout of the throughgoing rods spanning the cutouts and may be subsequently rewelded thereto. The cutouts 2 are then filled with grouting up to the level Lof the upper slab surface to form a continuous slab 2' as illustrated on the left in FIG. 1; if the slabs arepoured in place rather than precast, the cutouts 2 may of course be omitted.

The sealing strip 12 is of generally triangular cross section and culminates in a gable-shaped apex 12 which rises substantially to the top level of layer 4 and ribs 7 in a position of closest approach (FIG. 1) of the roadway sections and descends (FIG. 2) as these sections separate. Accumulating dirt and rubbish will thereby be lifted onto the road surface for removal by street-cleaning equipment.

In FIG. 3 I have shown an inversion of the clamping mechanism of FIGS. 1 and 2, the confronting ribs 20 of profiles 21 underlying here the edges of strip 24 which are overlain by bars 22 receiving the countersunk screws 25. Spacing rings 23 again limit the extent to which these clamping screws may be tightened and, in this embodiment, also resist adepression of the bars 22 by the traffic rolling over them. Bars 22, like the ribs 7 of the preceding embodiment, are level with the roadway surface of asphalt layers 26 supported by concrete slabs 27.

In the joints 30 of FIG. 4, the confronting ribs 31 form extensions of flanges 33 of two profiles 34 having upstanding webs 35, these profiles being approximately of inverted-T shape. In this embodiment the sealing strip 32 is clamped against the ribs 31 by means of stepped bars 36 whose reduced base portions 37 form spacers around clamping screws 38 passing therethrough. Here the clamped strip edges lie near the level of the upper surfaces of slabs 39, thus lower within the gap than in the preceding embodiments. This arrangement is therefore intended primarily for use with traction layers 40 of limited depth.

It will be noted that, even in the closeup position of FIG. I and 3 in which the apex of the strip reaches the roadway surface, the clamping members 7 or 22 flush with that surface are still separated bya gap of a width substantially greater than twice the thickness of strip 12 so that the flanks of the strip diverge downwardly at a sizable angle.

Iclaim:

1. In a roadway comprising a plurality of spacedly adjoining concrete slabs with generally horizontal upper surfaces and traction layers supported on said surfaces, the combination therewith of an expansion joint in a gap between a pair of said slabs, said expansion joint including two metal profiles on opposite sides of said gap and a flexible sealing strip spanning said gap; each of said profiles comprising a substantially horizontal flange received in a recess of the upper surface of a respective slab of said pair, an upstanding web rising from said flange to the top of said layer and resting on a ledge of said slab, and a rib flush with the top of said layers projecting integrally from said web into said gap while spacedly confronting a corresponding rib on the other profile; said profiles being provided with clamping means securing opposite edges of said strip to the undersides of the confronting ribs.

2. The combination defined in claim 1 wherein said profiles are provided with anchor means imbedded in said strip.

3. The combination defined in claim 2 wherein said anchor means comprises a set of loops secured to the underside of said flange.

4. The combination defined in claim 1 wherein said strip has an angular cross section with an upwardly pointing vertex substantially at the level of the top of said layer.

5. The combination defined in claim 1 wherein said strip consists of elastomeric material.

6. In a roadway comprising a plurality of spacedly adjoining concrete slabs with generally horizontal upper surfaces and traction layers supported on said surfaces, the combination therewith of an expansion joint in a gap between a pair of said slabs, said expansion joint including two metal profiles on opposite sides of said gap and a flexible sealing strip spanning said gap; each of said profiles comprising a substantially horizontal flange received in a recess of the upper surface of a respective slab of said pair, an upstanding web rising from said flange to the top of said layer, and a projection extending integrally from said web into said gap while spacedly confronting a corresponding projection on the other profile; said profiles being provided with clamping means securing opposite strip edges to the confronting projections of said profiles said projection being a continuous rib member; said clamping means comprising a bar member substantially coextensive with said rib member and vertically spaced therefrom for gripping said strip therebetween, one of said members underlying the corresponding edge of said strip, the other of said members overlying said corresponding edge and being substantially flush with the top of said layers; said strip having an angular cross section with an upwardly pointing apex substantially at the level of the top of said layer in a relative position of'said slabs in which said other of said members on one side of the slab is separated from the corresponding member on the other side of the slab by a distance substantially greater than twice the thickness of said strip whereby the latter forms two downwardly diverging flanks on opposite sides of said apex.

7. The combination defined in claim 6 wherein said one of said members is provided with a series of tapped holes and said other of said members is provided with a series of bores aligned with said holes, said clamping means further including screws with heads countersunk in said other of said members extending through said bores and matingly engaging said holes.

8. The combination defined in claim 7 further comprising spacing means interposed between said members for limiting the approach of said members toward each other upon a tightening of said screws. 

1. In a roadway comprising a plurality of spacedly adjoining concrete slabs with generally horizontal upper surfaces and traction layers supported on said surfaces, the combination therewith of an expansion joint in a gap between a pair of said slabs, said expansion joint including two metal profiles on opposite sides of said gap and a flexible sealing strip spanning said gap; each of said profiles comprising a substantially horizontal flange received in a recess of the upper surface of a respective slab of said pair, an upstanding web rising from said flange to the top of said layer and resting on a ledge of said slab, and a rib flush with the top of said layers projecting integrally from said web into said gap while spacedly confronting a corresponding rib on the other profile; said profiles being provided with clamping means securing opposite edges of said strip to the undersides of the confronting ribs.
 2. The combination defined in claim 1 wherein said profiles are provided with anchor means imbedded in said strip.
 3. The combination defined in claim 2 wherein said anchor means comprises a set of loops secured to the underside of said flange.
 4. The combination defined in claim 1 wherein said strip has an angular cross section with an upwardly pointing vertex substantially at the level of the top of said layer.
 5. The combination defined in claim 1 wherein said strip consists of elastomeric material.
 6. In a roadway comprising a plurality of spacedly adjoining concrete slabs with generally horizontal upper surfaces and traction layers supported on said surfaces, the combination therewith of an expansion joint in a gap between a pair of said slabs, said expansion joint including two metal profiles on opposite sides of said gap and a flexible sealing strip spanning said gap; each of said profiles comprising a substantially horizontal flange received in a recess of the upper surface of a respective slab of said pair, an upstanding web rising from said flange to the top of said layer, and a projection extending integrally from said web into said gap while spacedly confronting a corresponding projection on the other profile; said profiles being provided with clamping means securing opposite strip edges to the confronting projections of said profiles said projection being a continuous rib member; said clamping means comprising a bar member substantially coextensive with said rib member and vertically spaced therefrom for gripping said strip therebetween, one of said members underlying the corresponding edge of said strip, the other of said members overlying said corresponding edge and being substantially flush with the top of said layers; said strip having an angular cross section with an upwardly pointing apex substantially at the level of the top of said layer in a relative position of said slabs in which said other of said members on one side of the slab is separated from the corresponding member on the other side of the slab by a distance substantially greater than twice the thickness of said strip whereby the latter forms two downwardly diverging flanks on opposite sides of said apex.
 7. The combination defined in claim 6 wherein said one of said members is provided with a series of tapped holes and said other of said members is provided with a series of bores aligned with said holes, said clamping means further including screws with heads countersunk in said other of said members extending through said bores and matingly engaging said holes.
 8. The combination defined in claim 7 further comprising spacing means interposed between said members for limiting the approach of said members toward each other upon a tightening of said screws. 